Х - яблок всего.
х/2 +1/2 - дал маме
(х/2 +1/2)/ 2 +1/2 - дал брату
1 -осталось
х/2 + 1/2 + (х/2 + 1/2) / 2 +1/2 + 1 = х
х + 1 + х/2 + 1/2 + 1 + 2 = 2х
-0,5х = -4,5х
х = 9
1)
/////////////////////////////////////////////
--------(1)-------------------(2,5)--------------
\\\\\\\\\\\\\\\\\\\\\\\\\\
x∈(2,5;∞)
2){x≥1,5
{x≤3
//////////////////////////////////////////////////////
---------[1,5]----------------------[3]---------------
\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
x∈[1,5;3]
3
/////////////////////////////////////////////////////
------------(-2)---------------------(-1,5)----------------
\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
x∈(-2;-1,5)
4
{5x<5⇒x<1
{x<12
\\\\\\\\\\\\\\
---------(1)---------------------(12)-----------
///////////////////////////////////////////
x∈(-∞;1)
5
{x≤15
{x≥6
\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
--------[6]------------------[15]-----------
/////////////////////////////////////////
x∈[6;15]
6
{x>0
{x≥-7
/////////////////////////////////////////////
----------[-7]--------------------(0)----------------
\\\\\\\\\\\\\\\\\\
x∈(0;∞)
5а-2(х-2)=5а-2х-4
5а-2х+4=5а-2х-4
Ответ:нет неверно